DESCRIPTION: The epidemiology of HHV-8 transmission remains poorly understood. In industrialized countries, there is evidence for homosexual transmission but the seroprevalence is low in the general population. However, in sub-Saharan Africa HHV-8 seroprevalence increases gradually from infancy through adulthood, and rates exceeding 50 percent have been reported in the general population in some countries. There is some evidence that prostitutes are at increased risk and that HHV-8 infection is associated with High-risk heterosexual behavior. In 1993 the investigators established a prospective cohort study of prostitutes in Mombasa Kenya. Their pilot data suggest that these women are at substantial risk for HHV-8 infection, with an enrollment seroprevalence of 41 percent and annual incidence of 4.1 percent. They propose to study heterosexual transmission of HHV-8 in this cohort by evaluating seroprevalence, seroincidence, and correlates of prevalent and incident infection. Presence of HHV-8 DNA in cervical and vaginal secretions, as well as in saliva, plasma and PBMCs will be evaluated in chronically and acutely infected women to better understand factors that influence infectivity. They will also seek to determine whether there is a characteristic clinical illness associated with primary HHV-8 infection, as is suggested by preliminary analyses of 27 seroincident cases. Over 1,200 women have been enrolled to date over the past 7 years and about 150 new women join the study each year. Women are followed at monthly intervals with questionnaires, physical examinations, and serologic assays for precise timing of HHV-8 acquisition. Kaposi's sarcoma, the major morbidity associated with HHV-8, has become the leading cause of cancer in some African countries because of the concurrence of the HIV/AIDS epidemic. A better understanding of heterosexual transmission of HHV-8 is essential for the development of interventions strategies to prevent HHV-8 infection and associated malignancy.